Inflammation and tissue remodeling mediator expression during gingivitis: A comparison between experimental, naturally occurring gingivitis, and periodontal health.

BACKGROUND: The aim of this study is to evaluate the immune regulation and tissue remodeling responses during experimental gingivitis (EG) and naturally occurring gingivitis (NG) to provide a comprehensive analysis of host responses. Gingival crevicular fluid (GCF) was obtained from 2 human studies conducted in university settings. METHODS: The EG study enrolling 26 volunteers provided controls for the baseline (Day 0) from healthy disease-free participants, while Day 21 (the end of EG induction of the same group) was used to represent EG. Twenty-six NG participants age-matched with those of the EG group were recruited. GCF samples were analyzed for 39 mediators of inflammatory/immune responses and tissue remodeling using commercially available bead-based multiplex immunoassays. The differences in GI and mediator expression among groups were determined at a 95% confidence level (p ≤ 0.05) by a 2-way analysis of variance (ANOVA) with a post-hoc Tukey's test. RESULTS: Our findings showed that EG had a greater gingival index than NG and was healthy (p < 0.01 of all comparisons). Furthermore, EG showed significantly higher levels of MPO (p < 0.001), CCL3 (p < 0.05), and IL-1B (p < 0.001) than NG. In contrast, NG had increased levels of MIF (p < 0.05), Fractalkine (p < 0.001), angiogenin (p < 0.05), C3a (p < 0.001), BMP-2 (p < 0.001), OPN (p < 0.05), RANKL (p < 0.001), and MMP-13 (p < 0.001) than EG. CONCLUSIONS: Consistent with the findings from chronic (NG) versus acute (EG) inflammatory lesions, these data reveal that NG displays greater immune regulation, angiogenesis, and bone remodeling compared to EG.

The effect of cement versus screw-retained implant positioning in the esthetic zone on emergence angle: A proof of principle.

Choosing between screw-retained and cement-retained restorations in the esthetic zone may have a significant implication on the restorative contour. This study analyzes the effect of facial-palatal implant positioning on the facial emergence angle of implant restorations in the maxillary anterior region. 133 maxillary anterior implant cases were captured with intraoral scans and used to create digital prosthetic designs. The facial emergence angle of the restoration and the depth of the implant were determined using images at the mid-facial cross-section. Simple logistic and linear regression models were used to analyze the interrelation between the emergence angle, depth, and retention methods. The average facial emergence angle for all restorations in this study was 34.4 degrees. A significant difference was found in emergence angle between screw-retained and cement-retained groups, with an average emergence angle of 37.3 degrees and 27.9 degrees, respectively. There is no difference in the mean depth between those two groups. There is a strong negative linear relationship between depth and emergence angle for the screw-retained group. Overall, implant positioning in the anterior maxilla has a significant influence on emergence angle. Facial emergence angle is significantly greater for implants in screw-retained position. This may be partially alleviated by deeper implant placement.

Localized microbially induced inflammation influences distant healthy tissues in the human oral cavity.

Variation in human immune response to the same bacterial or viral pathogen is well established in the literature. Variation in immune response to microbial challenge has also been observed within the human oral cavity. Our recent study focused on characterizing observed variations in microbially induced gingival inflammation-resulting in three distinct clinical Inflammatory Responder Types (IRTs): High-IRT, Low-IRT, and Slow-IRT. Here, we applied a high-resolution temporal multiomic analysis during microbially induced inflammation in order to characterize the effects of localized oral inflammation on distant healthy tissues in young healthy adults. Our results highlight a nonlocalized subclinical effect with alterations in proinflammatory host mediators and an ecological shift toward dysbiosis within the subgingival microbiome in an IRT-dependent manner-despite maintained oral hygiene. Our results provide mechanistic insight into how healthy tissues within humans are influenced by distant localized inflammation and may ultimately become susceptible to disease.

Assessment of titanium release following non-surgical peri-implantitis treatment: A randomized clinical trial.

BACKGROUND: Peri-implantitis is a frequent finding. Initial treatment involves non-surgical debridement of the implant surface. Recent studies have found a correlation between titanium (Ti) particle release and peri-implantitis, yet there is a dearth of information regarding the effect of various non-surgical instrumentation on particle release or peri-implantitis resolution. METHODS: Patients with peri-implantitis were recruited for a randomized, blinded, parallel-group clinical trial. The implants were randomized to treatment composed of Ti curettes ("Mech" group) or implant-specific treatment composed of rotary polymer microbrushes ("Imp" group). Ti release in submucosal peri-implant plaque pre- and 8 weeks posttreatment was assessed as the primary outcome. Peri-implant probing depth, bleeding on probing, and suppuration on probing were evaluated and compared between groups. RESULTS: Thirty-four participants completed treatment; 18 were randomized to the Mech group and 16 to the Imp group. The groups were comparable for Ti levels and probing depths at baseline. A trend was noted for 10-fold greater Ti dissolution in the Mech group posttreatment compared to the Imp group (p = 0.069). The Imp group had a significant reduction in probing depth posttreatment (p = 0.006), while the Mech group reduction was not significant. CONCLUSION: Peri-implantitis treated non-surgically with implant-specific instruments (Imp group) had a significantly greater decrease in probing depth versus the Mech treatment group. This improvement was linked with a trend for less Ti release to the peri-implant plaque by the non-abrasive treatment.

Risk factors and longitudinal regenerative outcomes of sinus membrane perforation during lateral window sinus floor elevation: A retrospective analysis up to 9 years.

BACKGROUND: Lateral-window sinus floor elevation (LSFE) is a reliable procedure to reconstruct the posterior maxilla for implant therapy. This retrospective study aimed to investigate risk factors associated with Schneiderian membrane perforation (SMP) occurrence during LSFE and longitudinal regenerative outcomes following LSFE up to 9 years. METHODS: Patients who had LSFE between 2010 and 2019 were included. All demographic and surgical-related data were retrieved from existing electronic health records. Radiographs were used to evaluate the vertical dimensional changes of ridge and graft materials and the potential anatomic factors of SMP. RESULTS: A total of 122 LSFE procedures in 99 patients were included in the study. Mean ridge height gain and graft shrinkages were 9.5 ± 3.47 and 1.57 ± 2.85 mm. The influence of the healing period on graft shrinkage showed a positive trend; the longer the healing period, the greater the graft shrinkage (p = 0.09). The pathology in the sinus showed a positive correlation with SMP (p = 0.07). However, other anatomical factors did not negatively impact SMP and subsequent ridge height gain (p > 0.05). CONCLUSIONS: With inherent limitation, the findings with up to 9 years of follow-up indicate a consistent ridge remodeling lasting for about 3 years after LSFE procedures. SMP or membrane thickening may not significantly affect the ridge gain following LSFE. The healing period had the most significant influence on graft shrinkage, showing that the longer the healing time between LSFE and implant placement, the greater the graft shrinkage.

Clinical performance of hydrophilic, titanium-zirconium dental implants in patients with well-controlled and poorly controlled type 2 diabetes: One-year results of a dual-center cohort study.

BACKGROUND: This study assessed the clinical performance of hydrophilic dental implants in a patient cohort with type 2 diabetes mellitus (T2DM). METHODS: Subjects with T2DM of ≥2-years duration were allocated to either the well-controlled (WC; HbA1c ≤ 7.0%,) or poorly-controlled (PC; 7.5 < HbA1c < 10%) groups in a dual-center, prospective cohort study. Each subject received a single, titanium-zirconium (Ti-Zr) dental implant with a chemically-modified, hydrophilic (modSLA) surface in a posterior mandibular site. Postoperatively, subjects were followed at 1, 2, 4, 8, and 12-week intervals. Post-loading, subjects were followed at 3, 6, and 12-months. Clinical and radiographic parameters of implant success, and dental patient-reported outcomes were collected. RESULTS: Twenty-one dental patients (NWC  = 11; NPC  = 10; mean age: 66.8 ± 7.5 years) were enrolled and the 1-year implant success rate was 100%. Peri-implant bone levels were stable with 0.15 ± 0.06 mm mean marginal loss at 1 year without significant inter-group differences (P = 0.79). Postoperative pain was minimal at 1-week, and OHIP-5 scores decreased significantly over time as compared with preoperative levels (P < 0.001) suggesting significant improvement in patient-perceived oral health following implant therapy. CONCLUSIONS: Elevated HbA1c levels > 7.5% did not compromise 1-year success rates, or oral health-related quality of life in PC patients receiving modSLA, Ti-Zr implants. Given that implant placement up to 10% HbA1c significantly enhanced oral health-related quality of life without complications or morbidity, the safety and efficacy of implants to improve oral function in T2DM is supported, even without ideal glycemic control.

Integration of a new classification scheme for periodontal and peri-implant diseases through blended learning.

PURPOSE: In recent years, dental education has experienced a general shift toward an increased technology presence in education delivery and learning. This research examines the student-perceived efficacy of a blended learning approach (mixture of online content and face-to-face instruction) in a predoctoral periodontics curriculum to teach a new periodontal classification scheme to dental students in clinical training. METHODS: Participants were recruited from third- and fourth-year predoctoral periodontal classes at the University of Washington School of Dentistry. Students were administered a live lecture introducing the new classification system and given access to an online module with built in case quizzes and interactive activities. Upon completing the module, students were given a post-module survey to assess learning preferences, utilization of various learning methods, and student-perceived efficacy of blended learning. RESULTS: In a study group of 69 predoctoral dental students, the online module was the most preferred (52.2% ranked first) and utilized learning method for students (p < 0.001). Over 80% of students agreed or strongly agreed that they enjoyed using it and found it more effective than traditional lecture alone. Traditional lecture was preferred by 31.9% of students, and no students ranked the assigned reading as their first choice of learning method (p < 0.001). CONCLUSIONS: Our findings demonstrate higher student preference, utilization, and self-perceived efficacy of blended learning as compared to traditional assigned readings and lectures - supporting blended learning as a promising educational approach for predoctoral dental education.

Role of thin gingival phenotype and inadequate keratinized mucosa width (<2 mm) as risk indicators for peri-implantitis and peri-implant mucositis.

BACKGROUND: There is growing evidence on the impact of thin gingival phenotype (TnP) and inadequate keratinized mucosa width (KMW <2 mm) around dental implants on peri-implant health. This study investigated the role of TnP and inadequate KMW (<2 mm) as risk indicators for peri-implantitis and mucositis and on dental patient-reported outcomes. METHODS: Sixty-three patients with 193 implants (mean follow-up of 6.9 ± 3.7 years) were given a clinical and radiographic examination and a questionnaire to assess patient awareness of food impaction and pain/discomfort. Chi-squared tests and regression analysis for clustered data were used to compare outcomes. RESULTS: Implants with TnP had a statistically higher prevalence of peri-implantitis (27.1% versus 11.3%; PR, 3.32; 95% confidence interval (CI), 1.64-6.72; P = 0.001) peri-implant mucositis (42.7% versus 33%; PR, 1.8; 95% CI, 1.12-2.9; P = 0.016) and pain/discomfort during oral hygiene (25% versus 5%; PR, 3.7; 95% CI, 1.06-12.96; P = 0.044) than thick phenotype. Implants with inadequate KMW had a statistically higher prevalence of peri-implantitis (24.1% versus 17%; PR, 1.87; 95% CI, 1.07-3.25; P = 0.027) and peri-implant mucositis (46.6% versus 34.1%; PR, 1.53; 95% CI, 1-2.33; P = 0.05) and pain/discomfort during oral hygiene (28% versus 10%; PR, 2.37; 95% CI, 1.1-5.1; P = 0.027) than the adequate KMW. TnP was strongly associated with inadequate KMW (PR = 3.18; 95% CI, 1.69-6.04; P <0.001). CONCLUSION: TnP and inadequate KMW (<2 mm) may be significant risk indicators for peri-implant disease and pain/discomfort during brushing.

Interproximal open contacts between implant restorations and adjacent natural teeth as a risk-indicator for peri-implant disease-A cross-sectional study.

OBJECTIVES: The primary aim of this study was to investigate the relationship between interproximal open contacts and peri-implant disease. The secondary aim was to assess patient-reported outcome measures in relation to contact status. MATERIALS AND METHODS: A cross-sectional study was performed on 61 patients with 142 implants adjacent to at least one natural tooth. Patients underwent a clinical examination to assess contact status and width, plaque index (PI), gingival index (GI), periodontal probing depths (PPD), and bleeding on probing (BoP). Radiographic marginal bone level was measured in vertical bitewings taken within one year. A diagnosis was given to each implant. Last, subjects completed a brief questionnaire. Rao-scott chi-squared tests and generalized estimating equations (GEE) models were used to compare outcomes between groups. RESULTS: Seventy-seven (54.2%) implants were found to have ≥1 interproximal open contact. Sixty-five (45.8%) implants had closed contacts only. Implants with interproximal open contacts were significantly associated with peri-implant mucositis and peri-implantitis (p = .003) and increased prevalence of peri-implant disease (adjusted PR = 1.57; 95% CI: 1.09-2.27, p = .015). Open contact status was also associated with higher PPD (p = .045), PI scores (p = .036), and GI scores (p = .021). Open contact prevalence was 75.4% on the patient-level and 54.2% on the implant-level, involving the mesial surface of the implant restorations 68.5% of the time (p < .001). CONCLUSION: Interproximal open contacts between implant restorations and adjacent natural teeth are a risk indicator for peri-implant disease. Adequate contact between implant restorations and natural teeth may contribute to the health of peri-implant tissues.

Effect of implant cleaning on titanium particle dissolution and cytocompatibility.

BACKGROUND: Peri-implantitis treatments are mainly based on protocols for teeth but have not shown favorable outcomes for implants. The potential role of titanium dissolution products in peri-implantitis necessitate the consideration of material properties in devising treatment protocols. We assessed implant cleaning interventions on (1) bacterial removal from Ti-bound biofilms, (2) Ti surface alterations and related Ti particle dissolution, and (3) cytocompatibility. METHODS: Acid-etched Ti discs were inoculated with human peri-implant plaque biofilms and mechanical antimicrobial interventions were applied on the Ti-bound biofilms for 30 seconds each: (1) rotary nylon brush; (2) Ti brush; (3) water-jet on high and (4) low, and compared to sterile, untreated and Chlorhexidine-treated controls. We assessed colony forming units (CFU) counts, biofilm removal, surface changes via scanning electron microscopy (SEM) and atomic force microscopy (AFM), and Ti dissolution via light microscopy and Inductively-coupled Mass Spectrometry (ICP-MS). Biological effects of Ti particles and surfaces changes were assessed using NIH/3T3 fibroblasts and MG-63 osteoblastic cell lines, respectively. RESULTS: Sequencing revealed that the human biofilm model supported a diverse biofilm including known peri-implant pathogens. WJ and Nylon brush were most effective in reducing CFU counts (P < 0.01 versus control), whereas Chlorhexidine was least effective; biofilm imaging results were confirmatory. Ti brushes led to visible streaks on the treated surfaces, reduced corrosion resistance and increased Ti dissolution over 30 days of material aging as compared to controls, which increase was amplified in the presence of bacteria (all P-val < 0.05). Ti particles exerted cytotoxic effects against fibroblasts, whereas surfaces altered by Ti brushes exhibited reduced osteoconductivity versus controls (P < 0.05). CONCLUSIONS: Present findings support that mechanical treatment strategies selected for implant biofilm removal may lead to Ti dissolution. Ti dissolution should become an important consideration in the clinical selection of peri-implantitis treatments and a necessary criterion for the regulatory approval of instruments for implant hygiene.

The impact of a change in classification criteria on the prevalence of peri-implantitis: A cross-sectional analysis.

BACKGROUND: Peri-implantitis is a frequent finding but estimates of its prevalence vary widely. This may be due to the wide variety of disease definitions. In 2017 the World Workshop on Periodontal and Peri-implant Diseases and Conditions established new criteria for disease definitions. The aim of this study is to assess the potential impact of a new definition on the future reporting of peri-implant disease. METHODS: Data from a 2015 report of peri-implant prevalence were examined using the new diagnostic criteria. This cross-sectional study was performed on 95 patients with 220 implants who had their implants placed between 1998 and 2003. An examiner masked to the previous diagnosis examined the radiographs and patient data to make a diagnosis based on 3 mm of bone loss from the expected level of bone. This reanalysis was used to calculate the prevalence of peri-implant disease and generate new relative risk indicators. RESULTS: The mean follow-up time for the patients was 10.9 years. Using the 2017 criteria, peri-implant mucositis was found in 35.3% of the implants and 52.2% of the subjects, and peri-implantitis occurred in 8.7% of the implants and 15.2% of the subjects. This constituted a drop in peri-implantitis at both patient and implant level of nearly 50% from the prior analysis. Smoking at time of implant placement emerged as a new risk factor in this analysis that was not identified in the prior analysis. CONCLUSIONS: The new diagnostic criteria significantly reduce the reported prevalence of peri-implantitis and bring new risk factors into focus.

Modified SHI medium supports growth of a disease-state subgingival polymicrobial community in vitro.

Developing a laboratory model of oral polymicrobial communities is essential for in vitro studies of the transition from healthy to diseased oral plaque. SHI medium is an enriched growth medium capable of supporting in vitro biofilms with similar diversity to healthy supragingival inocula; however, this medium does not maintain the diversity of gram-negative bacteria more associated with subgingival plaque. Here, we systematically modified SHI medium components to investigate the impacts of varying nutrients and develop a medium capable of supporting a specific disease-state subgingival community. A diseased subgingival plaque sample was inoculated in SHI medium with increasing concentrations of sucrose (0%, 0.1%, 0.5%), fetal bovine serum (FBS) (0%, 10%, 20%, 30%, 50%), and mucin (0.1, 2.5, 8.0 g/L) and grown for 48 hrs, then the 16S rRNA profiles of the resulting biofilms were examined. In total, these conditions were able to capture 89 of the 119 species and 43 of the 51 genera found in the subgingival inoculum. Interestingly, biofilms grown in high sucrose media, although dominated by acidogenic Firmicutes with a low final pH, contained several uncultured taxa from the genus Treponema, information that may aid culturing these periodontitis-associated fastidious organisms. Biofilms grown in a modified medium (here named subSHI-v1 medium) with 0.1% sucrose and 10% FBS had a high diversity closest to the inoculum and maintained greater proportions of many gram-negative species of interest from the subgingival periodontal pocket (including members of the genera Prevotella and Treponema, and the Candidate Phyla Radiation phylum Saccharibacteria), and therefore best represented the disease community.

Endodontic Peri-implant Defects: A New Disease Entity.

Peri-implantitis is becoming a frequent complication observed around dental implants. An endodontic infection of a nearby tooth or an immediate implant placement in an inflamed bone socket from failing endodontic therapy has been associated with retrograde peri-implantitis (RPI), a condition that presents with radiographic lucency at the "apex" of an implant. However, current classification schemes do not capture endodontic lesions that may manifest as coronal or intrabony lesions associated with dental implants. As a result, such cases may be mistreated. Here we present for the first time 2 cases in which peri-implant bone loss occurred in the coronal half of the implant adjacent to a tooth with an endodontic-periodontic lesion and was resolved via endodontic therapy or tooth extraction as indicated. This proof of concept report aimed to introduce endodontic peri-implant ("endo-implant") defects and increase vigilance, which may help prevent overtreatment or mistreatment of such cases.

Biofilm as a risk factor in implant treatment.

This article summarizes the microbiological findings at dental implants, drawing distinctions between the peri-implant microbiome and the periodontal microbiome, and summarizes what is known regarding biofilm as a risk factor for specific stages of implant treatment. Targeted microbial analysis is reviewed as well as the latest results from open-ended sequencing of the peri-implant flora. At this time there remains a lack of consensus for a specific microbial profile that is associated with peri-implantitis, suggesting that there may be other factors which influence the microbiome such as titanium surface dissolution. Therapeutic interventions to address the biofilm are presented at the preoperative, perioperative, and postoperative stages. Evidence supports that perioperative chlorhexidine reduces biofilm-related implant complications and failure. Regular maintenance for dental implants is also shown to reduce peri-implant mucositis and implant failure. Maintenance procedures should aim to disrupt the biofilm without damaging the titanium dioxide surface layer in an effort to prevent further oxidation. Evidence supports the use of glycine powder air polishing as a valuable adjunct to conventional therapies for use at implant maintenance visits. For the treatment of peri-implantitis, nonsurgical therapy has not been shown to be effective, and while surgical intervention is not always predictable, it has been shown to be superior to nonsurgical treatment for decontamination of the implant surface that is not covered by bone.

Patient-Centered Risk Assessment in Implant Treatment Planning.

PURPOSE: To evaluate the current scientific evidence on estimating cumulative risk for biologic complications relating to dental implants and to develop a patient-centered risk assessment tool for establishing aggregate risk. MATERIALS AND METHODS: A review of the scientific literature on risk indicators relating to dental implants was completed with the goal of identifying and weighting individual risk indicators so aggregate biologic risk could be estimated. Three authors completed independent reviews of the literature, identifying 31 systematic reviews on risk indicators for biologic complications with dental implants, from which 24 potential risk indicators were considered. Due to inconclusive scientific data on risk indicators, a Delphi process was used to gather structured expert opinion to supplement findings from the literature. Eleven Delphi participants with expertise in prosthodontics or periodontics participated in two email exchanges and one face-to-face meeting to comment and debate on the initial identification and weighting of risk indicators, propose the addition or removal of risk indicators, and provide recommended clinical management for each risk indicator. RESULTS: After three rounds of debate, literature review, and additions and removals of various risk indicators, consensus (defined as 95% or more in agreement) was achieved on 20 risk indicators. The Delphi group concluded that the risk indicators of smoking, diabetes, antiresorptive agents, and cemented restorations should include subcategories to more accurately identify and represent patient-specific risk. Clinical recommendations based on individual and aggregate risk were established by consensus. CONCLUSION: The literature on risk indicators for biologic complications was conflicting and inconclusive. The Delphi method was used to identify and establish the weighting of individual risk indicators, resulting in a risk assessment tool for estimating aggregate risk.

Titanium as a modifier of the peri-implant microbiome structure.

BACKGROUND: Recent data support the implication of accelerated titanium dissolution products in peri-implantitis. It is unknown whether these dissolution products have an effect on the peri-implant microbiome, the target of existing peri-implantitis therapies. PURPOSE: This study assessed the relationship between the peri-implant microbiome, dissolved titanium levels, and peri-implantitis. MATERIALS AND METHODS: Clinical, microbiome, and titanium data were collected from a periodontal population having implants in function for 10 years. Clinical examinations were performed, and submucosal plaque samples were collected from the deepest site per implant. An aliquot of the sample was used for 16S rRNA gene sequencing, with the remainder analyzed for titanium quantity using mass spectrometry. Sequences were clustered into taxonomic units at 97% minimum sequence similarity using the QIIME pipeline approach. RESULTS: Fifteen implants were assessed. According to established case definitions, six had a diagnosis of peri-implantitis; nine were healthy. The genera Streptococcus, Prevotella and Haemophilus characterized peri-implant health. Peri-implantitis was associated with a marked increase in Veillonella. Quantities of dissolved titanium were identified in 40% of sites. Titanium presence was associated with peri-implant disease status (P = .02) and correlated to the first principal component of the microbiome (rho = 0.552) and its alpha-diversity (rho = -0.496). Canonical correlation analyses found that titanium levels, but not health or disease status of the implant, were significantly associated with the microbiota composition (P = .045). CONCLUSIONS: These findings suggest an association between titanium dissolution products and peri-implantitis and support a role for these products in modifying the peri-implant microbiome structure and diversity.

Restoration contour is a risk indicator for peri-implantitis: A cross-sectional radiographic analysis.

AIM: The purpose of this study was to determine whether restoration emergence angle was associated with peri-implantitis. MATERIALS AND METHODS: A data set consisting of 96 patients with 225 implants (mean follow-up: 10.9 years) was utilized. Implants were divided into bone-level and tissue-level groups, and radiographs were analysed to determine the restoration emergence angles, as well as restoration profiles (convex or concave). Peri-implantitis was diagnosed based on probing depth and radiographic bone loss. Associations between peri-implantitis and emergence angles/profiles were assessed using generalized estimating equations. RESULTS: Eighty-three patients with 168 implants met inclusion criteria. The prevalence of peri-implantitis was significantly greater in the bone-level group when the emergence angle was >30 degrees compared to an angle ≤30 degrees (31.3% versus 15.1%, p = .04). In the tissue-level group, no such correlation was found. For bone-level implants, when a convex profile was combined with an angle of >30 degrees, the prevalence of peri-implantitis was 37.8% with a statistically significant interaction between emergence angle and profile (p = .003). CONCLUSIONS: Emergence angle of >30 degrees is a significant risk indicator for peri-implantitis and convex profile creates an additional risk for bone-level implants, but not for tissue-level implants.

Consensus Conference Findings on Supragingival and Subgingival Air Polishing.

A consensus conference was convened to evaluate and address issues of safety and efficacy when using glycine powder in an air-powder jet device for supra- and subgingival applications during dental prophylaxis and periodontal maintenance. The conference reported the following conclusions: 1) Supra- and subgingival air polishing using glycine powder is safe and effective for removal of biofilms from natural tooth structure and restorative materials; 2) there is no evidence of soft-tissue abrasion when using glycine powder in an air-polishing device; 3) in periodontal probing depths of 1 mm to 4 mm, glycine-powder air polishing, using a standard air-polishing nozzle, is more effective at removing subgingival biofilm than manual or ultrasonic instruments; and 4) at probing depths of 5 mm to 9 mm, using a subgingival nozzle, glycine powder air polishing is more effective at removing subgingival biofilm than manual or ultrasonic instrumentation. This conference statement, supported by an industry grant, was drafted by a panel of distinguished dental professionals.